In modern telephony networks, service control points (SCPs) serve as an interface to telephony related databases, such as: call management services databases (CMSDB); line information databases (LIDB); and business services databases (BSDB). These databases are used, at least in part, to facilitate a variety of advanced intelligent network (AIN) related services including: find me service; follow me service; computer security service; call pickup service; store locator service; call waiting service; call block service; calling name delivery service; three way calling service; and 800 number services.
With particular regard to find me service, this service allows calls to be forwarded to another location. The difference between this feature and current call forwarding functionality is the ability to screen unwanted calls from forwarding. Only authorized callers are forwarded to the new location. Similarly, follow me service allows a number to be forwarded on a time schedule. The subscriber determines the time forwarding is to take place when the feature is invoked. Destinations can include both wired and wireless telephones or handsets.
Computer security service allows subscribers to prevent unauthorized callers from accessing a computer or application services. Only callers with the authorized access code or calling from an authorized number can access the services. The SS7 network delivers the calling party number to the destination end office. This number is then checked in a database located with a service control point (SCP), and, if authorized, is allowed to connect with the application. With call pickup service, when a call is placed to a number and is unanswered, the called party can be paged via radio pager. The called party can then dial a code from any telephone at any location and immediately be connected with the waiting caller. With regard to paging type services, manufacturers of such personal communications services (PCS) devices have to date developed two-way pagers that connect a caller with the party being paged. The pager is a two-way transceiver capable of receiving calls (pages) and connecting the caller with the paged party.
Store locator service allows businesses to advertise one number, and have callers automatically transferred to the nearest location based on the caller's telephone number. This allows businesses to advertise nationwide for all locations without special ads that are region specific. The calling party number is matched in a routing database located at an SCP, and the SCP provides the end office with the routing instructions based on the calling party number. With call routing service, businesses can reroute calls during periods of excessively high call volumes or after business hours.
It will be further appreciated that such telephony service databases may also be employed to provide communication service subscribers the flexibility to easily port their service from one communication service provider to another (i.e., number portability or local number portability). The application of such SCP-type database services is not limited to the traditional wired public switched telephone network (PSTN), but is also widely implemented in the wireless telecommunications industry. Typical wireless network communication database applications include: home location registers (HLRs), visitor location registers (VLRs), authentication centers (AuCs), and equipment identification registers (EIRs). In general, SCPs are the network elements that include database systems for providing the services discussed above.
It will also be appreciated that with the continuing convergence of traditional data networks and traditional telecommunication networks, the number and variety of converged or inter-network service related database applications designed to service the needs of combined data-telecommunications subscribers (e.g., presence service databases) will increase dramatically in the future.
With particular regard to traditional SCP network database elements, those skilled in the art of telecommunication network services will appreciate that an SCP is typically comprised of both a front end computer processor system and a back end database system. That is, the SCP front end processor (FEP) system typically does not store or contain the bulk data or information, but instead is the interface to a mainframe or minicomputer system that holds the actual database. Typically, there is a one-to-one correspondence between each FEP and an associated back end computing platform. In a signaling system 7 (SS7) signaling network environment, communication between an SCP front end and other nodes in the SS7 network is accomplished via dedicated SS7 communication links, while communication between the SCP front end and mainframe database back end is typically effected via a TCP/IP connection (or X.25 in older legacy systems). However, it should be noted that even within the telecommunications industry it is not uncommon to hear the term SCP used to describe the combination of front-end processors and mainframe back end database system.
From an accessibility standpoint, the SS7 network address component of an SCP front end is a point code (PC), while the address component of an application residing on the database back end is referred to as a subsystem number (SSN). A single SCP may contain multiple applications and databases, and as such, there may be multiple subsystem numbers associated with a single SCP point code. Consequently, each SCP must be assigned a unique SS7 network address PC, but may have multiple back end database subsystems provisioned under each unique SS7 network address PC.
Typically, the front end of an SCP located in an SS7 network can perform protocol conversion from SS7 to TCP/IP (or SS7 to X.25 in the case of legacy systems), or it may provide the capability of communicating with the associated back end database directly through the use of primitives. A primitive is an interface that provides access from one level of the protocol to another level. In the case of back end databases, each database is considered to be an application entity, and the protocol used to access and interface to each application entity is known as transaction capabilities application part or TCAP.
Shown in FIG. 1 is an example of a prior art telecommunications network, generally indicated by the numeral 100, that provides AIN-type functionality similar to that described above. Telecommunications network 100 includes an originating end office (EO) or service switching point (SSP) 110, a signal transfer point (STP) 112, a first SCP 116, a second SCP 120, and a third SCP 124. It will be appreciated from FIG. 1 that SSP 110 has a network address PC of 3-1-1, STP 112 has a PC of 2-1-1, SCP 116 has a PC of 1-1-1 and a SSN of 20, SCP 120 has a PC of 1-1-2 and a SSN of 20, and SCP 124 has a PC of 1-1-3 and SSN of 20. As further indicated in FIG. 1, SSP 110 is coupled to STP 112 via a dedicated SS7 communication link 114, which is in turn communicatively coupled to each of the three SCP nodes via dedicated SS7 communication links 118, 122, and 126. With regard to the SCP nodes 116, 120, and 124, it will be appreciated from FIG. 1 that each overall SCP node is comprised of a number of components or sub-systems. More particularly, SCP 116 generally includes a front end processor (FEP) 128, which is coupled to a back end database (BED) 130 via a communication link or bus 132.
Given the above description of network 100, it will be appreciated by one skilled in the art of telecommunication signaling operations that if, for instance, Calling Name (CNAM) service is requested by a subscriber that is serviced by SSP 110, then SSP 110 will be required to formulate and send a CNAM query-type SS7 signaling message to STP 112 via the dedicated SS7 communication link 114. If it is also assumed that a database application corresponding to SSN 20 of SCP 116 is provisioned to provide CNAM-type information, then CNAM query message will either be addressed directly to the PC & SSN of SCP 116 (i.e., PC: 1-1-1, SSN: 20), or the CNAM query message will be addressed so as to request a final destination address translation at the STP 112 (i.e., through global title translation). For purposes of illustration, it is assumed that global title translation service is not required and, consequently, that the CNAM query message is addressed directly to SCP 116 (i.e., PC: 1-1-1, SSN: 20). As such, the CNAM query message is received by STP 112 and subsequently routed over communication link 118 to FEP 128. FEP 128 in turn receives the CNAM query message, processes the message, and facilitates access to the CNAM data stored in the BED 130. Ultimately, a CNAM reply message addressed to SSP 110 (PC: 3-1-1) is formulated and transmitted back to STP 112, which in turn routes the message to SSP 110.
As described above, each complete SCP unit is equipped with a front end processor that is responsible for managing the unit's associated database resources. Such management functions include: protocol conversion, message parsing, administration of inbound queries and outbound responses, load sharing, etc. Each front end processor is integral with the SCP unit and consequently, there is a one-to-one relationship that exists between front end processors and SCP units. Front end processors are expensive, and what is needed is a way to reduce the overall cost of SCP units by allowing one front end processor to drive multiple SCP units.
Therefore, what is needed is a system and method of incorporating SCP front end processing functionality within a communications network routing node such that multiple SCP back ends can be serviced by the single routing node. Furthermore, the SS7 signaling links typically employed to connect to SCP units are capital intensive and expensive to maintain. Consequently, a method of connecting to SCP units that does not require dedicated, expensive SS7 signaling links is also needed.